The 200" Hale Telescope

On Palomar Mountain

© Selden Ball, December, 2007. All rights reserved.

Contents

0: Introduction.
1: Exterior Views.
2: Looking in from outside.
3: Inside the dome.

0: Introduction

These Cel:// URLs cause Celestia to display a model of the Hale Telescope and some images created using the telescope itself.

1: Exterior views

• Sunset on Palomar (triplanet conjunction)
• Hale at Sunset
• Hale Telescope
• Palomar Observatory
  Vertical view from above
• Palomar Observatory
  View from the South.

• Large Format Camera's field of view

  Open the observatory doors to see the entire field of view: type the command
  [Enter]Hale_Open_Door[Enter] or [Enter]hod[Enter]

  Initially, the telescope is tracking Tau Ceti. It will track whatever object you Select. For example, type h6 to observe Saturn. Most other planets are below the horizon at the time of this URL. (H is needed to select the Sun's planets. Otherwise you're asking Celestia to select the 6th planet of Tau Ceti, which the Hale telescope can't resolve.)

  Be patient: the telescope takes a while to slew from one target to another.

  You'll need increase magnification and turn off the LFC's fov image when observing planets. Its image blocks the center of the screen. When looking at highly magnified viewpoints, including those below, type the command
  [Enter]hhlfcfov[Enter]
  to hide the Large Format Camera's field of view image. That is short for
  [Enter]Hale_Hide_LFCFOV[Enter]

  The Field of View image you will then see is the much smaller fov of the adaptive optics' PHARO infra-red camera. (See below.)

  For convenience, the initial 1999 PALAO demonstration is viewed from a point-of-view some distance from the telescope, so you don't have to open doors or disable a field of view image.

• Using PHARO in 1999:
  • Neptune 1999: PALAO off (PALomar Adaptive Optics)
    Normal viewing provides a resolution of only about 1 arc second due to atmospheric disturbances.
  • Neptune 1999: PALAO on
    Adaptive optics can improve viewing to 0.1 arc second
    See also http://ao.jpl.nasa.gov/Palao/PalaoIndex.html

• Using PHARO in 2006:
  • Observing Neptune using PHARO
  • pov
    This shows the Point of View used for Celestia's observations as a red dot. It's in the dark, so turn up Celestia's ambient light to see where it is relative to the prime focus cage.
  • At pov observing (tiny, distant) Neptune
    Open the dome's doors (hod) and increase magnification to the maximum (hold down the comma key ",") Don't forget to turn off the large format camera's fov if you haven't already (hhlfcfov), leaving just PHARO's fov.
  • The field of view of the Large Format Camera
    24' in diameter (24' = 24 minutes of arc)
    You may need to hide the observatory's dome to see it.
    [Enter]Hale_Hide_Dome[Enter] or [Enter]hhd[Enter]

  • PHARO 40" & 25" fields of view (25" = 25 seconds of arc)
    (Palomar High Angular Resolution Observer)
    See also http://astrosun2.astro.cornell.edu/research/projects/PHARO//pharo.html

    The viewpoints below show Neptune using images created using PHARO. False colors are used to show the J, H and K infrared wavelength bands. See also http://www.astro.cornell.edu/~banfield/work/nepmovie/anim2.html and http://www.astro.cornell.edu/~banfield/work/urnmovie/anim2.html

  • Neptune 2006: AO on
  • Uranus 2006
    • AO FoV
    • 25" Fov & orbits
    • Closeup

2: Looking in from outside

These are viewpoints looking from outside the dome. To see the indicated feature, you'll also have to type a command or two to eliminate the obstructing dome and fixtures.

• To see inside, hide the dome. Type the command [Enter]Hale_Hide_Dome[Enter] or [Enter]hhd[Enter]
• The internal structure of the dome may still interfere. To hide it, type [Enter]Hale_Hide_Dome_Internal[Enter] or [Enter]hhdi[Enter]
• [Enter]hrd[Enter] and [Enter]hrdi[Enter] reveal them again.
• or select the appropriate command script in the directory \hale_commands\

• View labels
  To reveal or hide the labels, type the commands
  • [Enter]Hale_Reveal_Labels[Enter] or [Enter]hrlbl[Enter]
  • [Enter]Hale_Hide_Labels[Enter] or [Enter]hhlbl[Enter]

• Overhead cranes' hook
• Crane cables
  These commands move the hook and its cables:
  • [Enter]Hale_Up_Hook[Enter] or [Enter]huh[Enter]
  • [Enter]Hale_Down_Hook[Enter] or [Enter]hdh[Enter]
  • [Enter]Hale_Stop_Hook[Enter] or [Enter]hsh[Enter]

• windscreen height
  The Windscreen moves when different targets are selected.

• elevator from above
  These commands move the elevator up and down:
  • [Enter]Hale_Up_Elevator[Enter] or [Enter]hue[Enter]
  • [Enter]Hale_Down_Elevator[Enter] or [Enter]hde[Enter]
  • [Enter]Hale_Stop_Elevator[Enter] or [Enter]hse[Enter]

• view light paths
  There are 5 paths along which light can travel through the telescope.
  See also http://www.astro.caltech.edu/palomar/animations/lightpath.html
  Type these commands to visualize them:
  • [Enter]Hale_Hide_Light[Enter] or [Enter]hhl[Enter]
  • [Enter]Hale_Reveal_Light1[Enter] or [Enter]hrl1[Enter] (Prime focus)
  • [Enter]Hale_Reveal_Light2[Enter] or [Enter]hrl2[Enter] (Cassegrain focus)
  • [Enter]Hale_Reveal_Light3[Enter] or [Enter]hrl3[Enter] (Cassegrain-Coudé focus)
  • [Enter]Hale_Reveal_Light4[Enter] or [Enter]hrl4[Enter] (Coudé focus)
  • [Enter]Hale_Reveal_Light5[Enter] or [Enter]hrl5[Enter] (bridged Coudé focus)

• Contents of prime focus cage
  • By default, this Addon shows an observer guiding photographic plate, although nobody does that anymore.
    • [Enter]hrpo[Enter] (reveal observer)
    • [Enter]hhpo[Enter] (hide)
  • Palomar Large Format Camera:
    • [Enter]hrlfc[Enter] (reveal camera)
    • [Enter]hhlfc[Enter] (hide)
  • Laser Launch Telescope:
    • [Enter]hrlt[Enter] (reveal telescope)
    • [Enter]hhlt[Enter] (hide)

  For information about the laser guide-star for PALAO,
  see http://www.astro.caltech.edu/palomar/AO/

• laser light
  These commands turn the laser on and off
  • [Enter]Hale_Reveal_Laser_Beam[Enter] or [Enter]hrlb[Enter]
  • [Enter]Hale_Hide_Laser_Beam[Enter] or [Enter]hhlb[Enter]
• View laser trolley
  Selecting different targets causes the trolley and laser beams to move
• View laser trolley side
  To see the trolley from this viewpoint, you'll have to hide the yoke:
  • [Enter]hhy[Enter] (hide Yoke)

• watch movements
  Type any of the following commands:
  • [Enter]hlm[Enter] to lower the Coudé flat mirror
  • [Enter]hrc[Enter] to raise the Coudé flat mirror's crane
  • [Enter]hlc[Enter] to lower the Coudé flat mirror's crane
  • [Enter]hrm[Enter] to raise the Coudé flat mirror

• View dome base
  Type any of the following commands:
  • [Enter]hhd[Enter] to hide the dome
  • [Enter]hrd[Enter] to reveal the dome
  • [Enter]hhy[Enter] to hide the yoke
  • [Enter]hry[Enter] to reveal the yoke
    etc.

3: Inside the dome

From these viewpoints, you should be able to use your mouse to wander around and look at the models more closely. See also http://www.astro.caltech.edu/palomar/images/cutaway.jpg (500KB)

• mirror cover
  Type either of these commands:
  • [Enter]hoc[Enter] to open the mirror's cover
  • [Enter]hcc[Enter] to close the mirror's cover

• interior

  The tank for aluminizing the primary mirror is to the left and the telescope's cassegrain cage is to the right, enclosing PHARO and the optical bench for PALAO.